Use of two reels in obtaining high elongation



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Patented Mar. 31, 1936 UNITED STATES PATENT oFFicE USE OF TWO REELS IN OBTAINING HIGH ELONGATION Wall'e Application April 22, 1933, Serial No. 667,460

3 Claims.

Our present invention has to do with a new method for use in the spinning of artificial iilaments, but primarily has for its purpose to improve the physical properties in the wet spinning 5 of cuprarnmonium filaments.

One object of the present invention is to provide an improved arrangement whereby the physical qualities of the filaments may be more easily controlled within wide limits.

Another object of the present invention is to provide a means whereby the physical properties of the filaments are improved by passing the filaments to the take-up means under little or no tension.

Further another object of the present invention is to provide a, means whereby an increased elongation is the result, thereby obtaining a corresponding increase of elasticity in the filaments.

These and other objects will in part be pointed out and in part becomes obvious from a study of the following specification and attached drawing, in which:

The ligure is a diagrammatic side elevation of a preferred arrangement of apparatus as used in our new method of spinning filaments.

Heretofore in the wet spinning of cupram monium filaments, it has been the general practice to cause the bundle of filaments which have been extruded from the spinning outlet, to proceed downwardly through a funnel together with the precipitating liquid, whereupon, after the discharge from the spinning device proper, the threads were directed around a Monel metal or glass rod, and were then made to pass through a horizontal or inclined gutter or channel which comprised the acid guide or coagulating means. Thence the thread was led or passed over the take-up reel or bobbin. The above-mentioned acid guide being usually traversely reciprocable also acted as a thread guide for producing the desired cross winding on the take-up means. It is therefore plainly apparent that the drawing of the thread from the funnel is done entirely by 45 the movement of the collecting reel.

Inasmuch as the bundle of iilaments immediately after leaving the precipitating liquid is treated with the coagulating solution and is fairly solidified within the same, the stretching required to bring the filaments to the desired iineness is almost exclusively and preferably done by the precipitating liquid flowing in the same direction as the drawing off ofthe thread. It is then seen that while this stretching is mostly done by the precipitating liquid that the friction developed by drawing the thread around the glass or metal rod will also act to stretch the bundle of filaments. This added friction therefore places an even greater burden on the take-up means and it is the object of applicants device to bring the filaments to` the takeeup means under little or no tension, thereby eliminating the added stretch by said take-up .means which is not easily Acontrollable and makes for filaments of inferior physical qualities.

It has been found therefore by ,theapplicanta that the physical qualities of the yarn are greatly improved and easily controllable within wide limits, by positioning in the path of the filaments a conveying element, which doffs the filaments and delivers them to the aforementioned take-up means under greatly reduced tension or, as the case may be, with no tension at all, thus eliminating the act of dofng from the take-up means which has hitherto been one of the functions of the collecting device. It will therefore be seen that the take-up means merely acts to collect the yarn and that the tension can be more easily controlled by the insertion of the aforementioned conveying means into the path of the laments. A description of applicants methods now follows:

In the drawing is illustrated the preferred form in which the reference numeral i indicates the filaments which are extruded through the precipitating funnel 2 in the usual manner. A power driven roller t which is driven by a suitable source of power, means not shown, is positioned in place of the usual Monel metal or glass rod and the thread is passed under this roller to the acid guide 4, thence to the take-up reel 5 or bobbin as the case may be.

This power driven roller 3 usually has the same or nearly the same peripheral speed as the takeup reel 5, which obviously indicates that there is practically no tension between the reel 5 and the roller 3.

It is also quite obvious that the speed of the roller 3 can be varied to any desired extent. For example should the speed of roller 3 be increased over the speed of the take-up reel 5, the yarn would go through the acid guide under a slack and be delivered to the reel 5 with a certain amount or" slack which would therefore increase the elongation appreciably.

Should, however, an increase of strength be desired, the peripheral speed of the roller 3 could be made less than the peripheral speed of the take-up reel 5, thus increasing the tension.

However, the low results heretofore encountered in the elongation of cuprammonium silks Cil or ne filaments indicate the extent to which the threads have been stretched in spinning.

For example, the percentage of elongation hitherto attained has been 12% to 14% whereas the elongation attained by applicants preferred method is from 25% to 30% so it is readily apparent that quite an advance has been made.

The increased elongation makes greater elasticity which is extremely desirable to the Weaver, inasmuch as the threads are not so liable to break during the making of the cloth and also allows more latitude in the shrinkage that attends the weaving of the cloth. That is, the cloth may be brought back to its original width after weaving whereas heretofore, the Weaver had to allow an added width to make up for the usual loss of width in weaving.

We have found that in order to increase the elongation to a great degree, both in the Wet and in the dry state, two reels may be used. The best results are obtained when the second reel runs at a slightly slower speed than the first reel. By this mode of procedure the result is to deliver the yarn to the take-up means under little or no tension as brought out in our preferred form.

Having now set forth our invention as required by the patent statutes, what we desire to claim l. In the manufacture of articial laments with a high elongation both in the wet and dry state, the steps of spinning the filaments, drawing the laments out to the desired fineness entirely within the precipitating solution and at a greater rate than the laments are drawn by the flow of precipitating solution, passing them to a tension eliminating means, passing them through a coagulating medium, then passing the laments to a take-up device under little or no tension.

2. In the manufacture of artificial filaments with a high elongation both in the wet and dry state, the steps of spinning the filaments, drawing the filaments out to the desired iineness entirely Within the precipitating solution and at a greater rate than the larnents are drawn by the ow of precipitating solution, passing them to a power driven roller whereby the elongation may be controlled by the peripheral speed of said roller, passing them to a take-up device and collecting the filaments under little or no tension.

3. In the manufacture of artificial filaments with a high elongation both in the wet and dry state, the steps of spinning the filaments, drawing them out only in the initial precipitating state and imparting a greater stretch t0 the filaments than that stretch given by the oW of precipitating solution, then passing them through a coagulating medium to a take-up means under little or no tension.

HUGO HOFMANN. KURT RICHTER. 

